Image forming device

ABSTRACT

There is provided an image forming device which has an opening/closing portion rotatably mounted to a device main body, and at which plural cartridges accommodated in the device main body can be exposed due to the opening/closing portion being rotated. In the image forming device, a portion of an outer peripheral surface of a belt, which is provided at the opening/closing portion, is positioned at a cartridge side of the opening/closing portion. An opposing member is provided at the opening/closing portion so as to oppose the portion of the outer peripheral surface of the belt. A guide portion, which guides the opposing member such that the opposing member can slide with respect to the device main body, is provided at the device main body.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2005-215026, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming device which has an opening/closing portion rotatably mounted to a device main body, and at which plural cartridges accommodated in the device main body can be exposed by the rotating of the opening/closing portion.

2. Description of the Related Art

Color image forming devices generally have plural (e.g., four) process cartridges (see, for example, Japanese Patent Applications Laid-Open (JP-A) Nos. 2003-241466 and 2003-241620). In most cases, an opening/closing portion is mounted to the device main body, so that these plural process cartridges can be exposed for maintenance and the like. Hereinafter, an example of a conventional image forming device will be described with reference to an accompanying drawing.

As shown in FIG. 12, a conventional image forming device 81 has an opening/closing portion 80 which is rotatably mounted to the device main body. Plural process cartridges 86 and the like, which are accommodated in the device main body, can be exposed by the opening/closing portion 80 being rotated.

A belt outer peripheral surface 87E of a transfer belt 87 is disposed at the process cartridge side of the opening/closing portion 80. An opposing member (in FIG. 12, an attracting/holding roller) 90 is provided so as to oppose the belt outer peripheral surface 87E.

In order to make the height of the image forming device 81 low, the process cartridges 86 and the opposing member (in FIG. 12, the attracting/holding roller) 90 must be provided close to one another. However, if they are placed too close together, there is the problem that, at the time of opening and closing the opening/closing portion 80, the opposing member 90 interferes with the process cartridges 86. In a structure in which the process cartridges are disposed so as to be lined-up vertically, it is important to keep to height of the image forming device 81 low, and this problem becomes particularly serious.

SUMMARY OF THE INVENTION

In view of the aforementioned, the present invention provides an image forming device whose device height can be kept low.

A first aspect of the present invention provides an image forming device including: a device main body accommodating plural cartridges; an opening/closing portion which is rotatably mounted to the device main body, and which, by rotating, is able to expose the plural cartridges; a belt provided at the opening/closing portion, a portion of an outer peripheral surface of the belt being positioned at a cartridge side of the opening/closing portion; an opposing member provided at the opening/closing portion so as to oppose the portion of the outer peripheral surface of the belt; and a guide portion, provided at the device main body and guiding the opposing member such that the opposing member can slide with respect to the device main body.

The opposing member may be a blade, a scraper, a brush, an attracting/holding roller, a secondary transfer roller, a cleaner, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will be described in detail based on the following figures, wherein:

FIG. 1 is a side sectional view showing the structure of a printer relating to the embodiment of the present invention (a state in which a manual feed tray is open);

FIG. 2 is a side sectional view showing the structure of the printer relating to the embodiment of the present invention (a state in which a sheet feed cassette is pulled-out without opening the manual feed tray);

FIG. 3 is a side sectional view showing the structure of the printer relating to the embodiment of the present invention (a state in which the manual feed tray is closed and the sheet feed cassette is accommodated);

FIG. 4 is a side sectional view showing the structure of the printer relating to the embodiment of the present invention (a state in which an opening/closing member is open);

FIG. 5 is a partial side sectional view showing that a process cartridge does not impede rotational movement of an attracting/holding roller in the printer relating to the embodiment of the present invention (only a lowermost process cartridge among process cartridges is shown);

FIG. 6 is a partial perspective view of the opening/closing portion structuring the printer relating to the embodiment of the present invention;

FIG. 7 is a partial enlarged view of FIG. 6;

FIG. 8 is a side sectional view showing the structure of the printer relating to the embodiment of the present invention (a state in the midst of closing the opening/closing portion);

FIG. 9 is a side sectional view showing the structure of the printer relating to the embodiment of the present invention (a state in the midst of closing the opening/closing portion);

FIGS. 10A through 10C are schematic side views showing the attracting/holding roller being guided by guide rails at a time of closing the opening/closing portion, in the printer relating to the embodiment of the present invention;

FIGS. 11A through 11C are schematic side views showing the attracting/holding roller being guided by the guide rails at the time of closing the opening/closing portion, in the printer relating to the embodiment of the present invention; and

FIG. 12 is a partial side sectional view showing an arrangement of a process cartridge and an attracting/holding roller, which is an opposing member, in a conventional image forming device (only a lowermost process cartridge among process cartridges is shown).

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described hereinafter. As shown in FIGS. 1 and 2, a printer 1 relating to the embodiment of the present invention is a full-color printer. Note that the right side in FIG. 1 corresponds to the front side of the device, and the left side in FIG. 1 corresponds to the rear side of the device. Four process cartridges 3, 4, 5, 6 which are disposed in a vertical row substantially vertically, and a transfer belt 7 which is disposed along the process cartridges 3, 4, 5, 6, are provided within a printer main body 1M which structures the printer 1. The transfer belt 7 is opened, and the process cartridges 3, 4, 5, 6 can be installed and removed in a substantially horizontal direction into and from the open space. Photosensitive drums (image carriers) 11, 12, 13, 14 are provided at the process cartridges 3, 4, 5, 6, respectively.

The printer 1 has an ROS (Raster Output Scanner) 8 which carries out image exposure at the respective photosensitive drums 11, 12, 13, and 14. Electrostatic latent images formed on the photosensitive drums 11, 12, 13, 14 are respectively developed by toners of the colors of black (K), cyan (C), magenta (M), yellow (Y) at the process cartridges 3, 4, 5, 6. The ROS 8 which serves as an exposure device is structured from four semiconductor lasers which are driven and lit on the basis of image data corresponding to the respective colors of black (K), cyan (C), magenta (M), yellow (Y), and fθ lenses and polygon mirrors, and/or plural reflecting mirrors, for deflecting and scanning the four laser lights exiting from the four semiconductor lasers, and the like.

Beneath these process cartridges, the printer 1 has a sheet feed cassette 16 (see FIG. 2) which supplies sheets P which serve as transfer materials. A cassette accommodating section, which accommodates the sheet feed cassette 16 such that the sheet feed cassette 16 can be pulled-out therefrom, is formed at the printer main body 1M.

The printer 1 has a cover-like opening/closing portion 20, which structures the device side wall portion at the pull-out side (the front side in FIGS. 1 through 4) of the sheet feed cassette 16 above the sheet feed cassette 16. The opening/closing portion 20 is provided so as to be able to open and close the side surface of the device by being able to rotate around a rotation fulcrum J which is provided at the lower portion of the cassette accommodating portion. By opening the opening/closing portion 20, the process cartridges 3, 4, 5, 6 can be exposed and can be replaced, and maintenance with respect to paper jams or the like can be carried out in the state in which the photosensitive drums 11, 12, 13, 14 are exposed. The opening/closing portion 20 has a manual feed tray 22 which can open and close. A desired sheet P can be fed, from the exterior of the printer main body I M, through the manual feed tray 22.

In addition to the structures described above, the printer 1 also has a fixing device carrying out fixing processing on the sheet P to which toner images have been transferred; a conveying path 9 for double-sided printing, which conveys the sheet P, on whose one surface an image has been fixed by the fixing device, to the transfer section again in a state in which the obverse and reverse of the sheet P are reversed; a control circuit controlling operations of the printer; a controller structured from image processing circuits and the like, which carry out image processings on image signals; electrical circuits formed from a high-voltage power source circuit and the like; and the like. Note that, in FIGS. 1 through 4, T indicates a discharge tray into which the sheet P, on which an image has been formed, is discharged. This discharge tray T is disposed integrally with the top portion of the printer main body 1M.

(Opening/Closing Portion)

A structure that the rotational operation of the opening/closing portion 20 can be smooth, and that can position the opening/closing portion 20 when the opening/closing portion 20 is closed, will be described in detail hereinafter.

As shown in FIGS. 1 through 4, the opening/closing portion 20 is rotatably mounted to the printer main body 1M. By rotating and opening the opening/closing portion 20, the process cartridges 3, 4, 5, 6 accommodated in the printer main body 1M are exposed.

A belt outer peripheral surface 7E of a transfer belt 7 is positioned at the process cartridge side of the opening/closing portion 20 (toward the inside of the device main body) (see FIG. 5). (Here, the belt outer peripheral surface 7E refers to a portion of the outer peripheral surface of the belt 7, that faces the process cartridge side.) An attracting/holding roller 30 is provided at the opening/closing portion 20 so as to oppose the belt outer peripheral surface 7E. The roller surface of the attracting/holding roller 30 presses against the belt outer peripheral surface 7E.

A guide portion, which slidably guides the attracting/holding roller 30, is provided at the printer main body 1M. The attracting/holding roller 30 slides as the opening/closing portion 20 is opened and closed.

As shown in FIGS. 5 through 7, in the present embodiment, the attracting/holding roller 30 is provided as the opposing member. However, instead of the attracting/holding roller, a blade, a scraper, a brush, a secondary transfer roller, a cleaner, or the like may be provided.

The guide portion will be described hereinafter by using FIG. 8 through FIGS. 11A-11C. Guide rails (guide members) 34 which guide the attracting/holding roller 30 from the lower side, link members 36 which support the attracting/holding roller 30 at the both end portions, and tension coil springs 38 (see FIGS. 11A through 11C) which are mounted to the link members 36 and urge the attracting/holding roller 30 toward the belt outer peripheral surface 7E, are provided at the printer 1 as a guide portion 32. The guide rails 34 are provided at the printer main body 1M (see FIGS. 8 and 9).

As shown in FIGS. 11A through 11C, the tension coil springs 38 are hooked on projections (not shown) which are formed at the link members 36 and the opening/closing portion 20, and are disposed so as to urge the attracting/holding roller 30 toward a driving roller 40 which abuts the belt inner peripheral surface side of the transfer belt 7. When the opening/closing portion 20 is open and the attracting/holding roller 30 is not abutting the guide rails 34 (see FIG. 11A), the link members 36 is pulled by the tension coil springs 38, and further, movement thereof is restricted by stoppers (not shown), so that the attracting/holding roller 30 is positioned diagonally downward of the driving roller 40.

When the opening/closing portion 20 which is open is rotated in the closing direction, a rotating shaft projecting from the end portions of the attracting/holding roller 30 abuts the top surfaces of the guide rails 34 (see FIGS. 8, 9, and 10A). Note that in FIG. 8 through FIGS. 10A through C, for simplification, the drawings show the attracting/holding roller 30 abutting the guide rail 34, but in actuality, the rotating shaft of the attracting/holding roller 30 abuts the guide rails 34.

When the opening/closing portion 20 is rotated further in the closing direction, the attracting/holding roller 30 is guided by and slides on the top surfaces of the guide rails 34, such that the heightwise position of the attracting/holding roller 30 gradually rises (see FIG. 10B).

When the opening/closing portion 20 is completely closed, the attracting/holding roller 30 reaches a predetermined position (see FIG. 10C). The mounting positions of the tension coil springs 38 are determined such that, in this state, the tension coil springs 38 urge the link members 36 downward. In this way, there is a simple structure in which the guide rails 34 guide the attracting/holding roller 30 only from the lower side.

As described above, in the present embodiment, even if the attracting/holding roller 30 is disposed near to the cartridge 6, the attracting/holding roller 30 and the cartridge 6 do not interfere with one another at times of opening and closing of the opening/closing portion 20, and therefore, the height of the device can be kept low. Further, because interference between the attracting/holding roller 30 and the cartridge 6 can be avoided regardless of the position of the rotating fulcrum J of the opening/closing portion 20, the degrees of freedom in selecting the position of the rotating fulcrum J increase.

The tension coil springs 38 are provided as described above. In this way, the urging forces which urge the attracting/holding roller 30 toward the driving roller 40 change in accordance with the open/closed state of the opening/closing portion 20. In the state in which the opening/closing portion 20 is open, the urging forces are released, and it is possible to make it such that sheets which have jammed are not nipped by the attracting/holding roller 30 and the driving roller 40. Therefore, the operability improves. In addition, the slid position of the attracting/holding roller 30 can be made to coincide with the open/closed position of the opening/closing portion 20, and problems in the sliding operation and the like can be prevented. Therefore, the reliability improves.

Further, because the link members 36 are provided as described above, the shaft-receiving portions of the attracting/holding roller 30, and the supporting members which support the attracting/holding roller 30 in order to slide the attracting/holding roller 30, can be structured integrally. In this way, the structure can be simplified, and costs can be reduced.

Because the attracting/holding roller 30 is provided at the opening/closing portion 20, maintenance, such as cleaning of the attracting/holding roller 30 and the like, is easy. Further, when the transfer belt 7 is replaced, the attracting/holding roller 30 can be replaced at the same time. Therefore, the workability at the time of replacing the attracting/holding roller 30 is good, and lifetime care of the attracting/holding roller 30 is easy. Moreover, it is easy to make the diameter of the attracting/holding roller 30 large, and the guidability at the time when a sheet is thrust-in improves. In addition, by opening the opening/closing portion 20, sheets which are nipped between the transfer belt 7 and the attracting/holding roller 30 can be easily removed, and the ability to clear paper jams is good.

The guide rails 34, which support the attracting/holding roller 30 while guiding the attracting/holding roller 30 at the times when the opening/closing portion 20 opens and closes, are provided at the printer main body 1M. In this way, when opening the opening/closing 20 portion, the locus of movement of the sliding of the attracting/holding roller 30 can be controlled reliably, and it is possible to reliably avoid interference between the attracting/holding roller 30 and the cartridge 6.

As described above, in accordance with the present invention, an image forming device in which the height of the device is kept low can be realized.

In the image forming device which is structured in this way, the opposing member is provided at the opening/closing portion, and not at the device main body. Therefore, the opening/closing portion can be positioned highly accurately.

Further, because the opposing member slides as the opening/closing portion is opened and closed, it is possible for the cartridges and the opposing member to not interfere with one another even if the opposing member is disposed near to the cartridges, and the height of the device can be kept low. Further, because interference between the opposing member and the cartridges can be avoided regardless of the position of the rotation fulcrum of the opening/closing portion, the degrees of freedom in selecting the position of the rotation fulcrum increase.

An embodiment of the present invention was described by using a full-color printer as an example. However, note that the above-described embodiment is an example, and the present invention can be implemented by making various changes within a scope which does not deviate from the gist thereof. Further, the scope of the present invention is, of course, not limited to the above-described embodiment. 

1. An image forming device comprising: a device main body accommodating a plurality of cartridges; an opening/closing portion which is rotatably mounted to the device main body, and which, by rotating, is able to expose the plurality of cartridges; a belt provided at the opening/closing portion, a portion of an outer peripheral surface of the belt being positioned at a cartridge side of the opening/closing portion; an opposing member provided at the opening/closing portion so as to oppose the portion of the outer peripheral surface of the belt; and a guide portion, provided at the device main body and guiding the opposing member such that the opposing member can slide with respect to the device main body.
 2. The image forming device of claim 1, wherein the belt is a conveying belt which conveys a sheet, and the opposing member is an attracting/holding roller which electrostatically attracts and holds a sheet against the outer peripheral surface of the belt.
 3. The image forming device of claim 2, wherein a guide member, which guides the attracting/holding roller at times when the opening/closing portion is opening and closing, is disposed at the device main body as a structural member of the guide portion.
 4. The image forming device of claim 3, wherein the guide member is provided so as to guide the attracting/holding roller from below, and when the opening/closing portion is closing, a heightwise position of the attracting/holding roller rises by sliding due to the guide member.
 5. The image forming device of claim 4, further comprising an urging member urging the attracting/holding roller toward a roller which abuts an inner peripheral surface side of the belt.
 6. The image forming device of claim 5, wherein urging force of the urging member varies in accordance with an open/closed state of the opening/closing portion.
 7. The image forming device of claim 4, wherein the attracting/holding roller slides due to an axial center thereof moving.
 8. The image forming device of claim 4, further comprising an urging member urging the attracting/holding roller in order to slide the attracting/holding roller.
 9. The image forming device of claim 1, wherein a shaft-receiving portion of the opposing member, and a supporting member which supports the opposing member in order to slide the opposing member, are structured by a single part.
 10. The image forming device of claim 1, wherein the belt and the opposing member are integrally structured so as to be replaceable. 